/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package com.feilong.lib.org.apache.http.config;

import com.feilong.lib.org.apache.http.annotation.Contract;
import com.feilong.lib.org.apache.http.annotation.ThreadingBehavior;
import com.feilong.lib.org.apache.http.util.Args;

/**
 * Socket configuration.
 *
 * @since 4.3
 */
@Contract(threading = ThreadingBehavior.IMMUTABLE)
public class SocketConfig implements Cloneable{

    public static final SocketConfig DEFAULT = new Builder().build();

    private final int                soTimeout;

    private final boolean            soReuseAddress;

    private final int                soLinger;

    private final boolean            soKeepAlive;

    private final boolean            tcpNoDelay;

    private final int                sndBufSize;

    private final int                rcvBufSize;

    private final int                backlogSize;

    SocketConfig(final int soTimeout, final boolean soReuseAddress, final int soLinger, final boolean soKeepAlive, final boolean tcpNoDelay,
                    final int sndBufSize, final int rcvBufSize, final int backlogSize){
        super();
        this.soTimeout = soTimeout;
        this.soReuseAddress = soReuseAddress;
        this.soLinger = soLinger;
        this.soKeepAlive = soKeepAlive;
        this.tcpNoDelay = tcpNoDelay;
        this.sndBufSize = sndBufSize;
        this.rcvBufSize = rcvBufSize;
        this.backlogSize = backlogSize;
    }

    /**
     * Determines the default socket timeout value for non-blocking I/O operations.
     * <p>
     * Default: {@code 0} (no timeout)
     * </p>
     *
     * @return the default socket timeout value for non-blocking I/O operations.
     * @see java.net.SocketOptions#SO_TIMEOUT
     */
    public int getSoTimeout(){
        return soTimeout;
    }

    /**
     * Determines the default value of the {@link java.net.SocketOptions#SO_REUSEADDR} parameter
     * for newly created sockets.
     * <p>
     * Default: {@code false}
     * </p>
     *
     * @return the default value of the {@link java.net.SocketOptions#SO_REUSEADDR} parameter.
     * @see java.net.SocketOptions#SO_REUSEADDR
     */
    public boolean isSoReuseAddress(){
        return soReuseAddress;
    }

    /**
     * Determines the default value of the {@link java.net.SocketOptions#SO_LINGER} parameter
     * for newly created sockets.
     * <p>
     * Default: {@code -1}
     * </p>
     *
     * @return the default value of the {@link java.net.SocketOptions#SO_LINGER} parameter.
     * @see java.net.SocketOptions#SO_LINGER
     */
    public int getSoLinger(){
        return soLinger;
    }

    /**
     * Determines the default value of the {@link java.net.SocketOptions#SO_KEEPALIVE} parameter
     * for newly created sockets.
     * <p>
     * Default: {@code false}
     * </p>
     *
     * @return the default value of the {@link java.net.SocketOptions#SO_KEEPALIVE} parameter.
     * @see java.net.SocketOptions#SO_KEEPALIVE
     */
    public boolean isSoKeepAlive(){
        return soKeepAlive;
    }

    /**
     * Determines the default value of the {@link java.net.SocketOptions#TCP_NODELAY} parameter
     * for newly created sockets.
     * <p>
     * Default: {@code true}
     * </p>
     *
     * @return the default value of the {@link java.net.SocketOptions#TCP_NODELAY} parameter.
     * @see java.net.SocketOptions#TCP_NODELAY
     */
    public boolean isTcpNoDelay(){
        return tcpNoDelay;
    }

    /**
     * Determines the default value of the {@link java.net.SocketOptions#SO_SNDBUF} parameter
     * for newly created sockets.
     * <p>
     * Default: {@code 0} (system default)
     * </p>
     *
     * @return the default value of the {@link java.net.SocketOptions#SO_SNDBUF} parameter.
     * @see java.net.SocketOptions#SO_SNDBUF
     * @since 4.4
     */
    public int getSndBufSize(){
        return sndBufSize;
    }

    /**
     * Determines the default value of the {@link java.net.SocketOptions#SO_RCVBUF} parameter
     * for newly created sockets.
     * <p>
     * Default: {@code 0} (system default)
     * </p>
     *
     * @return the default value of the {@link java.net.SocketOptions#SO_RCVBUF} parameter.
     * @see java.net.SocketOptions#SO_RCVBUF
     * @since 4.4
     */
    public int getRcvBufSize(){
        return rcvBufSize;
    }

    /**
     * Determines the maximum queue length for incoming connection indications
     * (a request to connect) also known as server socket backlog.
     * <p>
     * Default: {@code 0} (system default)
     * </p>
     * 
     * @return the maximum queue length for incoming connection indications
     * @since 4.4
     */
    public int getBacklogSize(){
        return backlogSize;
    }

    @Override
    protected SocketConfig clone() throws CloneNotSupportedException{
        return (SocketConfig) super.clone();
    }

    @Override
    public String toString(){
        final StringBuilder builder = new StringBuilder();
        builder.append("[soTimeout=").append(this.soTimeout).append(", soReuseAddress=").append(this.soReuseAddress).append(", soLinger=")
                        .append(this.soLinger).append(", soKeepAlive=").append(this.soKeepAlive).append(", tcpNoDelay=")
                        .append(this.tcpNoDelay).append(", sndBufSize=").append(this.sndBufSize).append(", rcvBufSize=")
                        .append(this.rcvBufSize).append(", backlogSize=").append(this.backlogSize).append("]");
        return builder.toString();
    }

    public static SocketConfig.Builder custom(){
        return new Builder();
    }

    public static SocketConfig.Builder copy(final SocketConfig config){
        Args.notNull(config, "Socket config");
        return new Builder().setSoTimeout(config.getSoTimeout()).setSoReuseAddress(config.isSoReuseAddress())
                        .setSoLinger(config.getSoLinger()).setSoKeepAlive(config.isSoKeepAlive()).setTcpNoDelay(config.isTcpNoDelay())
                        .setSndBufSize(config.getSndBufSize()).setRcvBufSize(config.getRcvBufSize())
                        .setBacklogSize(config.getBacklogSize());
    }

    public static class Builder{

        private int     soTimeout;

        private boolean soReuseAddress;

        private int     soLinger;

        private boolean soKeepAlive;

        private boolean tcpNoDelay;

        private int     sndBufSize;

        private int     rcvBufSize;

        private int     backlogSize;

        Builder(){
            this.soLinger = -1;
            this.tcpNoDelay = true;
        }

        public Builder setSoTimeout(final int soTimeout){
            this.soTimeout = soTimeout;
            return this;
        }

        public Builder setSoReuseAddress(final boolean soReuseAddress){
            this.soReuseAddress = soReuseAddress;
            return this;
        }

        public Builder setSoLinger(final int soLinger){
            this.soLinger = soLinger;
            return this;
        }

        public Builder setSoKeepAlive(final boolean soKeepAlive){
            this.soKeepAlive = soKeepAlive;
            return this;
        }

        public Builder setTcpNoDelay(final boolean tcpNoDelay){
            this.tcpNoDelay = tcpNoDelay;
            return this;
        }

        /**
         * @since 4.4
         */
        public Builder setSndBufSize(final int sndBufSize){
            this.sndBufSize = sndBufSize;
            return this;
        }

        /**
         * @since 4.4
         */
        public Builder setRcvBufSize(final int rcvBufSize){
            this.rcvBufSize = rcvBufSize;
            return this;
        }

        /**
         * @since 4.4
         */
        public Builder setBacklogSize(final int backlogSize){
            this.backlogSize = backlogSize;
            return this;
        }

        public SocketConfig build(){
            return new SocketConfig(soTimeout, soReuseAddress, soLinger, soKeepAlive, tcpNoDelay, sndBufSize, rcvBufSize, backlogSize);
        }

    }

}
